To resolve the issue:

1. Open IIS Manager, go to Sites > SMEX Web Site, then click Bindings... on the right pane.

   

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2. Double-click https, then check if there is an assigned SSL Certificate.

   

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3. If there is no SSL certificate assigned, click Select button.
4. Assign a new certificate, and then click Save.
5. Restart the following services:
   • World Wide Web Publishing Service
   • ScanMail Master Service
6. Confirm if the issue is resolved by logging in to the SMEX Management Console.

If the issue persists, collect logs using Case Diagnostic Tool and submit it to Trend Micro Technical Support.